I. Field
The present disclosure relates generally to communication, and more specifically to techniques for estimating data-to-pilot ratio (D2P) in a wireless communication system.
II. Background
Wireless communication systems are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, etc. These systems may be multiple-access systems capable of supporting multiple users by sharing the available system resources. Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal FDMA (OFDMA) systems, and Single-Carrier FDMA (SC-FDMA) systems.
In a wireless communication system, a base station may transmit traffic data, control data, and pilot to one or more terminals. As used herein, the term “data” can refer to traffic data or control data. Traffic data is also commonly referred to as user data, packet data, etc. Control data is also commonly referred to as overhead data, signaling, etc. Pilot is data that is known a priori by both the base station and the terminals. A terminal may use the pilot for various purposes such as channel estimation, demodulation, decoding, etc.
The base station may transmit data at a particular power level and may transmit pilot at the same or different power level to a terminal. The terminal may need to ascertain the data-to-pilot ratio (D2P), which is the ratio of transmit power for data to transmit power for pilot. D2P may also be referred to as traffic-to-pilot ratio (T2P) for traffic data, overhead-to-pilot ratio (O2P) for control data, power offset between data and pilot, etc. For example, D2P may be used by a demodulator and/or a decoder to calculate their decision metrics. It is desirable to accurately estimate D2P when this is not known.